View source for Minix

{{Short description|Unix-like operating system}}
{{Use dmy dates|date=February 2022}}
{{Infobox OS
| name = MINIX
| logo = Minix3 Logo.png
| logo size = 100px
| screenshot = Minix 3.3.0 login prompt 2 screenshot.png
| caption = The MINIX 3.3.0 [[login]] prompt
| screenshot_alt = The MINIX 3.3.0 login prompt
| developer = [[Andrew S. Tanenbaum]], et al.
| source model = [[Open-source software|Open-source]]
| kernel type = [[Microkernel]]
| userland = [[BSD]] ([[NetBSD]])
| supported platforms = [[IBM PC compatible]]s, [[Motorola 68000 series|68000]], [[SPARC]], [[Atari ST]], [[Amiga]], [[Macintosh]], [[SPARCstation]], [[Intel 386]], [[NS320xx|NS32532]], [[ARM architecture|ARM]], [[Inmos]] [[transputer]], [[Intel Management Engine]]<ref>{{Cite web|url=http://blog.ptsecurity.com/2017/04/intel-me-way-of-static-analysis.html|title=Intel ME: The Way of Static Analysis|access-date=2017-07-04|archive-date=2017-07-01|archive-url=https://web.archive.org/web/20170701161110/http://blog.ptsecurity.com/2017/04/intel-me-way-of-static-analysis.html|url-status=dead}}</ref>
| family = [[Unix-like]]
| released = {{Start date and age|1987}}
| latest release version = 3.3.0<ref>{{cite web|website=[[Phoronix]]|url=https://www.phoronix.com/scan.php?page=news_item&px=MTc4OTk|title=Minix 3.3 Released With Cortex-A8 ARM Support, NetBSD Userland Compatibility|author=Michael Larabel|date=2014-09-16|access-date=11 May 2020|archive-date=25 March 2022|archive-url=https://web.archive.org/web/20220325073122/https://www.phoronix.com/scan.php?page=news_item&px=MTc4OTk|url-status=live}}</ref>
| latest release date = {{Start date and age|2014|09|16|df=yes}}
| latest preview version = 3.4.0rc6<ref>{{Cite web |url=https://www.phoronix.com/scan.php?page=news_item&px=MINIX-3.4-RC6-Released |title=MINIX 3.4 RC6 Released - Phoronix |access-date=18 June 2018 |archive-date=18 March 2022 |archive-url=https://web.archive.org/web/20220318093024/https://www.phoronix.com/scan.php?page=news_item&px=MINIX-3.4-RC6-Released |url-status=live }}</ref>
| latest preview date = {{Start date and age|2017|05|09|df=yes}}
| marketing target = [[Teaching]] (v1, v2)<br/>[[Embedded system]]s (v3)
| programmed in = [[C (programming language)|C]]
| language = [[English language|English]]
| update model = Compile from [[source code]]
| package manager = N/A
| working state = Abandoned
| license = 2005: [[BSD licenses|BSD 3-Clause]]{{efn|name=BSD-4-Clause-MINIX|BSD 3-Clause with a fourth clause}}<ref name="bsd34clause">{{cite web|title=The MINIX license|url=http://www.minix3.org/license.html|access-date=2005-11-24|archive-url=https://web.archive.org/web/20051124074039/http://www.minix3.org/license.html|archive-date=2005-11-24|url-status=dead}}</ref><br/>2000: [[BSD licenses|BSD 3-Clause]]<ref>{{cite web|title=MINIX license change|url=https://groups.google.com/g/comp.os.minix/c/tBv9PBZiLys/m/MvK3BN4NKtEJ|access-date=2023-12-23|archive-url=https://web.archive.org/web/20221206110556/https://groups.google.com/g/comp.os.minix/c/tBv9PBZiLys/m/MvK3BN4NKtEJ|archive-date=2022-12-06|url-status=live}}</ref><ref name=license-2000>{{cite web|title=MINIX is now available under the BSD license|url=http://minix1.woodhull.com/faq/mxlicense.html|access-date=2021-06-14|archive-date=2006-05-08|archive-url=https://web.archive.org/web/20060508041900/http://minix1.woodhull.com/faq/mxlicense.html|url-status=live}}</ref><ref name="retroactive-2000">{{cite web|title=Minix|url=https://www.minix-vmd.org/pub/minix/|quote=''The Minix license changed in April 2000, and applies retroactively to all previous Minix distributions, even though they still carry the old, more restrictive license within.''|access-date=2021-06-15|archive-date=2006-10-13|archive-url=https://web.archive.org/web/20061013051221/http://www.minix-vmd.org/pub/minix/|url-status=live}}</ref><br/>1995: [[Proprietary software|Proprietary]]<ref>{{cite web|title=License (1.7.0 to 2.0.2)|url=http://www.cs.vu.nl/ftp/minix/LICENSE|access-date=2021-06-14|archive-date=1997-07-26|archive-url=https://web.archive.org/web/19970726010847/http://www.cs.vu.nl/ftp/minix/LICENSE|url-status=dead}}</ref><br/>1987: [[Proprietary software|Proprietary]]<ref>{{cite web|title=Minix versions and their use in teaching|url=https://minix1.woodhull.com/teaching/teach_ver.html |access-date=14 June 2021|archive-date=2006-07-11|archive-url=https://web.archive.org/web/20060711224110/http://minix1.woodhull.com/teaching/teach_ver.html|url-status=live}}</ref>
| website = {{URL|www.minix3.org}}
}}

'''MINIX''' is a [[Unix-like]] [[operating system]] based on a [[microkernel]] [[Software architecture|architecture]], first released in 1987 and written by American-Dutch computer scientist [[Andrew S. Tanenbaum]]. It was designed as a clone of the [[Unix]] operating system<ref name=":0">{{Cite web |last=Anthes |first=Gary |title=Timeline: 40 Years Of Unix |url=https://www.computerworld.com/article/1698275/timeline-40-years-of-unix.html |access-date=2025-02-13 |website=[[Computerworld]]}}</ref> and one that could run on affordable, [[Intel 8086]]-based [[home computer]]s; MINIX was targeted for use in classrooms by [[computer science]] students at universities.<ref>{{Cite web |last1=Bentson |first1=Randolph |title=The Humble Beginnings of Linux |url=https://dl.acm.org/doi/fullHtml/10.5555/324785.324786 |access-date=2024-11-21 |website=[[Association for Computing Machinery]]}}</ref><ref name=":0" />

Its name comes from ''mini-Unix''. MINIX was initially [[Source-available software|proprietary source-available]], but was relicensed under the [[BSD licenses|BSD 3-Clause]] to become [[free and open-source]] in 2000.<ref name="license-2000" /><ref>{{Cite web |last=Byfield |first=Bruce |date=August 1, 2010 |title=An Introduction to MINIX {{!}} Linux Journal |url=https://www.linuxjournal.com/article/10754 |access-date=2024-12-05 |website=www.linuxjournal.com}}</ref> MINIX was ported to various additional platforms in the 1990s, and version 2.0 was released in 1997 and was the first to be [[POSIX]] compliant.<ref name="who-wrote-linux-notes">{{cite web |last=Tanenbaum |first=Andrew S. |author-link=Andrew S. Tanenbaum |date=20 May 2004 |title=Some Notes on the "Who wrote Linux" Kerfuffle, Release 1.5 |url=http://www.cs.vu.nl/~ast/brown/ |access-date=20 August 2016 |url-status=dead |archive-url=https://web.archive.org/web/20100818183310/http://www.cs.vu.nl/~ast/brown/ |archive-date=18 August 2010}}</ref><ref name="minix3-faq">{{cite web |last1=Tanenbaum |first1=Andrew S. |author1-link=Andrew S. Tanenbaum |last2=Woodhull |first2=Albert S. |last3=Sambuc |first3=Lionel |date=11 March 2015 |url=http://wiki.minix3.org/doku.php?id=faq |title=MINIX 3 FAQ |access-date=20 August 2016 |url-status=dead |archive-url=https://web.archive.org/web/20190426190210/https://wiki.minix3.org/doku.php?id=faq |archive-date=26 April 2019}}</ref> Starting with [[MINIX 3]], released in 2005, the primary aim of development shifted from education to the creation of a [[high availability|highly reliable]] and [[Self-management (computer science)|self-healing]] microkernel OS.

==Implementation==

===MINIX 1.0===
[[Andrew S. Tanenbaum]] created MINIX at [[Vrije Universiteit]] in [[Amsterdam]] to exemplify the principles conveyed in his [[textbook]], ''[[Operating Systems: Design and Implementation]]'' (1987). (Despite sharing a name, it has no relation to the older MINIX from Digital Systems House, Inc.<ref>{{cite magazine |title=MINIX advertisement |url=https://archive.org/details/sim_computerworld_1979-07-30_13_31/page/n39/ |access-date=22 March 2022 |magazine=Computerworld |issue=31 |date=1979-07-30 |volume=13 |page=38}}</ref> based on [[Ancient UNIX|AT&T Unix]] code.)

An abridged 12,010 lines of the [[C (programming language)|C]] [[source code]] of the [[Kernel (operating system)|kernel]], [[Memory management|memory manager]], and [[file system]] of MINIX 1.0 are printed in the book. [[Prentice-Hall]] also released MINIX source code and [[executable binary|executable binaries]] on [[floppy disk]] with a reference manual. MINIX 1 was system-call compatible with [[Seventh Edition Unix]].<ref>{{cite book |last1=Tanenbaum |first1=Andrew S. |author1-link=Andrew S. Tanenbaum |last2=Woodhull |first2=Albert S. |year=1997 |url=https://archive.org/details/operatingsystems00tane |title=Operating Systems Design and Implementation |publisher=Prentice Hall |isbn=0-13-638677-6 |access-date=2 August 2011 |edition=Second |orig-year=1986 |oclc=35792209 |url-access=registration}}</ref>

Tanenbaum originally developed MINIX for compatibility with the [[IBM PC]] and [[IBM PC/AT]] [[microcomputer]]s available at the time.

===MINIX 1.4===
There is a version of MINIX floating around that supports the Peripheral Technology PT68K-2 and PT68K-4 computers. The PT68K-2 and the PT68K-4 are both 68000 based computers with a standard 8 bit IBM PC [[ISA bus]] that has 6 connectors on the main board. It was ported to the PT68K machines by Gary Mills and Sidney Thompson. The port was adapted from the Atari port since it too is a 68000 based machine. The PT68K version has added support for the PT XT-[[integrated drive electronics|IDE]] card from Peripheral Technology. It currently only supports the [[IBM Monochrome Display Adapter|MDA]] display adapter (no [[Color Graphics Adapter|CGA]], [[Enhanced Graphics Adapter|EGA]] or [[VGA]]). For this reason, it has not yet been ported to the PT68K-5 (aka CDS68020). There is an [[SD Card]] [[disk image|image]] available from https://github.com/mevenson/minix-for-the-PT68K-2-4.

===MINIX 1.5===
MINIX 1.5, released in 1991, included support for [[MicroChannel]] [[IBM PS/2]] systems and was also [[ported]] to the [[Motorola 68000 series|68000]] and [[SPARC]] architectures, supporting the [[Atari ST]], [[Amiga]], [[Macintosh]],<ref>{{cite web|url=https://github.com/macminix|title=MacMinix|website=[[GitHub]]|access-date=8 August 2014|archive-date=26 February 2021|archive-url=https://web.archive.org/web/20210226193955/https://github.com/macminix|url-status=live}}</ref> and [[Sun Microsystems|Sun]] [[SPARCstation]] [[computer platform]]s. There were also unofficial ports to [[Intel 386]] [[PC compatible]]s (in [[32-bit]] [[protected mode]]), [[National Semiconductor]] [[NS320xx|NS32532]], [[ARM architecture|ARM]] and [[Inmos]] [[transputer]] processors. [[Meiko Scientific]] used an early version of MINIX as the basis for the [[MeikOS]] operating system for its transputer-based [[Computing Surface]] [[parallel computer]]s.

===MINIX 2.0===
[[File:MINIX 2.0.4 Startup Login.png|thumb|MINIX 2.0.4 system startup and login prompt]]
[[File:MINIX 2.0.4 Shell Interaction.png|thumb|MINIX 2.0.4 [[Unix shell|shell]] interaction]]

Demand for the 68k-architectures waned, however, and MINIX 2.0, released in 1997, was only available for the [[x86]] and [[Solaris (operating system)|Solaris]]-hosted SPARC architectures. It was the subject of the second edition of Tanenbaum's textbook, cowritten with Albert Woodhull and was distributed on a [[CD-ROM]] included with the book. MINIX 2.0 added [[POSIX]].1 compliance, support for 386 and later processors in 32-bit mode and replaced the [[Amoeba (operating system)|Amoeba]] network protocols included in MINIX 1.5 with a [[TCP/IP]] stack.  A version of MINIX running as a user process under [[SunOS]] and [[Solaris (operating system)|Solaris]] was also available, a simulator named SMX (operating system) or just ''SMX'' for short.<ref>{{cite web|url=http://www.minix3.org/previous-versions/CD-ROM-2.0/README.TXT|title=Welcome to MINIX|format=TXT|date=22 July 2005|access-date=2 August 2011|first1=Andrew S.|last1=Tanenbaum|author-link1=Andrew S. Tanenbaum|first2=Albert S.|last2=Woodhull|first3=Kees|last3=Bot|archive-date=17 April 2016|archive-url=https://web.archive.org/web/20160417173558/http://www.minix3.org/previous-versions/CD-ROM-2.0/README.TXT|url-status=live}}</ref><ref>{{cite web |url=http://www.csd.uoc.gr/~hy345/assignments/99b/smx_howto.html |title=Installing and running MINIX for Solaris (SMX) |access-date=2 August 2011 |first=M. |last=Flouris |archive-date=12 May 2016 |archive-url=https://web.archive.org/web/20160512214241/http://www.csd.uoc.gr/~hy345/assignments/99b/smx_howto.html |url-status=dead }}</ref>

Version 2.0.3 was released in May 2001. It was the first version after MINIX had been relicensed under the [[BSD licenses|BSD-3-Clause]] license, which was retroactively applied to all previous versions.<ref name="bsd3clause">{{cite web|title=BSD-3-Clause|url=http://www.cs.vu.nl/pub/minix/LICENSE|access-date=2021-06-14|archive-date=2000-04-14|archive-url=https://web.archive.org/web/20000414094106/http://www.cs.vu.nl/pub/minix/LICENSE|url-status=dead}}</ref>

====Minix-vmd====
Minix-vmd is a variant of MINIX 2.0 for Intel [[IA-32]]-compatible processors, created by two Vrije Universiteit researchers, which adds [[virtual memory]] and support for the [[X Window System]].

===MINIX 3===
{{Main|MINIX 3}}
[[File:Minix 3.png|thumb|MINIX 3 running [[X Window System|X11]] with the [[twm]] window manager]]
[[File:The MINIX 3 Microkernel Architecture.png|thumb|Architecture of MINIX 3]]

MINIX 3 was publicly announced on 24 October 2005 by Tanenbaum during his keynote speech at the [[Association for Computing Machinery]] (ACM) Symposium on Operating Systems Principles (SOSP). Although it still serves as an example for the new edition of Tanenbaum's textbook, coauthored by Albert S. Woodhull, it is comprehensively redesigned to be "usable as a serious system on resource-limited and embedded computers and for applications requiring high reliability."<ref>{{cite journal |last1=Herder |first1=J. N. |last2=Bos |first2=H. |last3=Gras |first3=B. |last4=Homburg |first4=P. |last5=Tanenbaum |first5=A. S. |author5-link=Andrew S. Tanenbaum |date=July 2006 |title=MINIX 3: a highly reliable, self-repairing operating system |doi=10.1145/1151374.1151391 |journal=ACM SIGOPS Operating Systems Review |volume=40 |issue=3 |pages=80–89 |s2cid=30216714}}</ref>

MINIX 3 currently supports [[IA-32]] and [[ARM architecture]] systems. It is available in a [[live CD]] format that allows it to be used on a computer without installing it on the hard drive, and in versions compatible with hardware emulating and virtualizing systems, including [[Bochs]], [[QEMU]], [[VMware Workstation]] and [[VMware Fusion|Fusion]], [[VirtualBox]], and [[Microsoft Virtual PC]].

Version 3.1.2 was released on 18 April 2006. It was the first version after MINIX had been relicensed under the [[BSD licenses|BSD-3-Clause]] license with a new fourth clause.<ref name="3.1.2 license">{{cite web|title=License |website=[[GitHub]] |url=https://github.com/Stichting-MINIX-Research-Foundation/minix/blob/v3.1.2/LICENSE|access-date=2021-06-15|archive-date=2021-06-15|archive-url=https://web.archive.org/web/20210615005833/https://github.com/Stichting-MINIX-Research-Foundation/minix/blob/v3.1.2/LICENSE|url-status=live}}</ref>

[[File:Minix3.png|upright=1.1|thumb|right|MINIX 3.1.7 running [[X Window System|X11]] with the [[Equinox Desktop Environment|EDE]]]]
Version 3.1.5 was released on 5 November 2009. It contains [[X11]], [[emacs]], [[Vi (text editor)|vi]], [[C compiler|cc]], [[GNU Compiler Collection|gcc]], [[perl]], [[Python (programming language)|python]], [[Almquist shell|ash]], [[Bash (Unix shell)|bash]], [[zsh]], [[ftp]], [[ssh]], [[telnet]], [[Pine (e-mail client)|pine]], and over 400 other common [[Unix]] utility programs. With the addition of X11, this version marks the transition away from a text-only system. In many cases it can automatically restart a crashed driver without affecting running processes. In this way, MINIX is self-healing and can be used in applications demanding high reliability. MINIX 3 also has support for [[virtual memory]] management, making it suitable for desktop OS use.<ref>{{cite web|url=http://groups.google.com/group/minix3/msg/86c914a0c13376fe|title=New to minix|date=10 November 2010|access-date=2 August 2011|first=Ulrich|last=Schmidt|archive-date=28 May 2013|archive-url=https://web.archive.org/web/20130528083817/http://groups.google.com/group/minix3/msg/86c914a0c13376fe|url-status=live}}</ref> Desktop applications such as [[Firefox]] and [[OpenOffice.org]] are not yet available for MINIX 3 however.

[[File:MINIX 3.2 Top Command.png|thumb|MINIX 3.2 running the "[[top (software)|top]]" system monitoring command]]
As of version 3.2.0, the [[User space|userland]] was mostly replaced by that of [[NetBSD]] and support from [[pkgsrc]] became possible, increasing the available software applications that MINIX can use. [[Clang]] replaced the prior compiler (with [[GNU Compiler Collection|GCC]] now having to be manually compiled), and [[GDB]], the [[GNU Debugger]], was [[ported]].<ref name=wiki-releases>{{cite web|title=MINIX Releases|url=http://wiki.minix3.org/en/MinixReleases|work=wiki.minix3.org|access-date=29 February 2012|url-status=dead|archive-url=https://web.archive.org/web/20120531025416/http://wiki.minix3.org/en/MinixReleases|archive-date=31 May 2012}}</ref><ref>{{Cite web |last=Vervloesem |first=Koem |date=7 March 2012 |title=MINIX 3.2: A microkernel with NetBSD applications |url=https://lwn.net/Articles/485658/ |website=[[lwn.net]] |access-date=17 June 2018 |archive-date=17 June 2018 |archive-url=https://web.archive.org/web/20180617220042/https://lwn.net/Articles/485658/ |url-status=live }}</ref>

MINIX 3.3.0, released in September 2014, brought ARM support.

MINIX 3.4.0RC, Release Candidates became available in January 2016.<ref>{{Cite web|url=http://download.minix3.org/iso/snapshot/|title=Index of /iso/snapshot/|website=download.minix3.org|access-date=2016-10-14|archive-date=25 February 2013|archive-url=https://web.archive.org/web/20130225110512/http://download.minix3.org/iso/snapshot/|url-status=live}}</ref> However, a stable release of MINIX 3.4.0 is yet to be announced, and MINIX development has been dormant since 2018.<ref>{{Cite web|url=https://git.minix3.org/index.cgi?p=minix.git;a=summary|title=git.minix3.org Git - minix.git/summary|website=git.minix3.org|access-date=2022-09-23|archive-date=16 January 2016|archive-url=https://web.archive.org/web/20160116100026/https://git.minix3.org/index.cgi?p=minix.git;a=summary|url-status=live}}</ref>

MINIX supports many programming languages, including [[C (programming language)|C]], [[C++]], [[FORTRAN]], [[Modula-2]], [[Pascal (programming language)|Pascal]], [[Perl]], [[Python (programming language)|Python]], and [[Tcl]].

Over 50 people attended MINIXCon 2016, a conference to discuss the history and future of MINIX.<ref>{{Cite web|url=http://www.minix3.org/conference/2016/program.html|title=MINIXCon 2016|website=www.minix3.org|access-date=2016-10-14|archive-date=3 June 2018|archive-url=https://web.archive.org/web/20180603231446/http://www.minix3.org/conference/2016/program.html|url-status=live}}</ref>

All Intel chipsets post-2015 are running MINIX 3 internally as the software component of the [[Intel Management Engine]].<ref>{{Cite web|url=http://blog.ptsecurity.com/2017/08/disabling-intel-me.html|title=Positive Technologies research|website=blog.ptsecurity.com|access-date=2017-09-06|archive-date=28 August 2017|archive-url=https://web.archive.org/web/20170828150536/http://blog.ptsecurity.com/2017/08/disabling-intel-me.html|url-status=dead}}</ref><ref>{{Cite web |last=Vaughan-Nichols |first=Steven |date=6 November 2017 |title=MINIX: Intel's hidden in-chip operating system |url=https://www.zdnet.com/article/minix-intels-hidden-in-chip-operating-system/ |website=[[ZDNET]] |language=en |access-date=19 April 2019 |archive-date=3 August 2023 |archive-url=https://web.archive.org/web/20230803092513/https://www.zdnet.com/article/minix-intels-hidden-in-chip-operating-system/ |url-status=live }}</ref>

==Relationship with Linux==

===Early influence===
[[Linus Torvalds]] used and appreciated MINIX,<ref>{{cite news |last=Moody |first=Glyn |date=2015-08-25 |title=How Linux was born, as told by Linus Torvalds himself |url=http://arstechnica.co.uk/business/2015/08/how-linux-was-born-as-told-by-linus-torvalds-himself/ |newspaper=Ars Technica |access-date=2015-08-25 |archive-date=25 August 2015 |archive-url=https://web.archive.org/web/20150825165300/http://arstechnica.co.uk/business/2015/08/how-linux-was-born-as-told-by-linus-torvalds-himself/ |url-status=live }}</ref> but his design deviated from the MINIX architecture in significant ways, most notably by employing a [[monolithic kernel]] instead of a [[microkernel]]. This was disapproved of by Tanenbaum in the [[Tanenbaum–Torvalds debate]]. Tanenbaum explained again his rationale for using a microkernel in May 2006.<ref>{{cite web|url=http://www.cs.vu.nl/~ast/reliable-os|title=Tanenbaum-Torvalds Debate: Part II|date=12 May 2006|access-date=2 August 2011 |first=Andrew S. |last=Tanenbaum |author-link1=Andrew S. Tanenbaum}}</ref>

Early [[Linux kernel]] development was done on a MINIX host system, which led to [[Linux]] inheriting various features from MINIX, such as the [[MINIX file system]]. [[Eric Raymond]] claimed that Linus hasn't actually written Linux from scratch, but rather reused source code of MINIX itself to have working codebase. As the development progressed, MINIX code was gradually phased out completely.<ref>{{cite book|first1=Eric|last1=Raymond|author-link1=Eric Raymond|date=1999|title=The Cathedral & the Bazaar|title-link=The Cathedral and the Bazaar|publisher=[[O'Reilly Media]]|page=33|isbn=1-56592-724-9}}</ref>

===''Samizdat'' claims===
In his 2004 book, ''[[Samizdat (book)|Samizdat]]'', Kenneth Brown of [[Alexis de Tocqueville Institution|AdTI]] claimed that much of the Linux kernel was copied from MINIX.<ref>{{cite web |url=http://adti.net/samizdat/brown.reply.june.04.html |archive-url=http://webarchive.loc.gov/all/20041022073106/http://www.adti.net/samizdat/brown.reply.june.04.html |url-status=usurped |archive-date=22 October 2004 |title=Samizdat's critics… Brown replies |date=4 June 2004 |access-date=2 August 2011 |publisher=Alexis de Tocqueville Institution |first=Kenneth |last=Brown |author-link=Kenneth Brown (author)}}</ref>
These accusations were rebutted universally—most prominently by Tanenbaum, who strongly criticised Brown and published a long rebuttal on his own personal Web site, also claiming that Brown was funded by [[Microsoft]].<ref name=who-wrote-linux-notes/><ref name=minix3-faq/>

==Licensing==
At the time of MINIX's original development, its [[software license|license]] was relatively liberal. Its licensing fee was very small ($69) relative to those of other operating systems. Tanenbaum wished for MINIX to be as accessible as possible to [[student]]s, but his publisher was unwilling to offer material (such as the source code) that could be copied freely, so a restrictive license requiring a nominal fee (included in the price of Tanenbaum's book) was applied as a compromise. This prevented the use of MINIX as the basis for a freely distributed software system.

When [[free and open-source]] Unix-like operating systems such as [[Linux]] and [[386BSD]] became available in the early 1990s, many [[volunteer]] [[software developer]]s abandoned MINIX in favor of these. In April 2000, MINIX became [[free and open-source software]] under the [[BSD licenses|BSD-3-Clause]] license, which was retroactively applied to all previous versions.<ref name="bsd3clause"/><ref name="retroactive-2000"/>  However, by this time other operating systems had surpassed its capabilities, and it remained primarily an operating system for students and [[hobbyist]]s. In late 2005, MINIX was relicensed with a fourth clause added to the [[BSD licenses|BSD-3-Clause]] license.<ref name="bsd34clause"/>

== Compared to other teaching operating systems ==
{{Teaching OS}}

==See also==
{{Portal|Free and open-source software}}
*[[MINIX file system]]
*[[Redox (operating system)|Redox]], an operating system in Rust using a MINIX-like kernel

==Notes==
{{reflist|group=lower-alpha}}

==References==
{{Reflist|30em}}

==External links==
{{sisterlinks|auto=1|d=Q187906|b=Minix 3}}
*{{Official website|http://www.MINIX3.org/}}
*{{github|Stichting-MINIX-Research-Foundation}}
*[http://minix1.woodhull.com The Minix Operating System (Minix 2 support)]
*[https://web.archive.org/web/20100818183310/http://www.cs.vu.nl/~ast/brown/ History of MINIX from Andrew Tanenbaum]
*{{YouTube|bx3KuE7UjGA|MINIX 3: a Modular, Self-Healing POSIX-compatible Operating System}}

{{Unix-like}}
{{FOSS}}
{{Microkernel}}
{{Authority control}}

{{DEFAULTSORT:Minix}}
[[Category:Minix| ]]
[[Category:1987 software]]
[[Category:Computer-related introductions in 1987]]
[[Category:ARM operating systems]]
[[Category:X86 operating systems]]
[[Category:Computer science in the Netherlands]]
[[Category:Dutch inventions]]
[[Category:Educational operating systems]]
[[Category:Free software operating systems]]
[[Category:Information technology in the Netherlands]]
[[Category:Lightweight Unix-like systems]]
[[Category:Microkernel-based operating systems]]
[[Category:Microkernels]]
[[Category:Operating system distributions bootable from read-only media]]
[[Category:Software using the BSD license]]
[[Category:Unix variants]]